Dual string packer construction



Oct. 4, 1966 M. L. CROW DUAL STRING PACKER CONSTRUCTION Original Filed July 26, 1961 5 Sheets-Sheet l INVENTOR 4 Morgan L. Crow BY Maw ATTORNEY Oct. 4, 1966 M. CROW DUAL STRING PACKER CONSTRUCTION 5 Sheets-Sheet 2 Original Filed July 26. 1961 Morgan L. Crow W i ATTORNEY Oct. 4, 1966 M. L. CROW DUAL STRING PACKER CONSTRUCTION 5 Sheets-Sheet 3 Original Filed July 26. 1961 INVENTOR Morgan L. Crow ATTORNEY M. L. CROW DUAL STRING PACKER CONSTRUCTION Oct. 4, 1966 5 Sheets-Sheet 4 Original Filed July 26. 1961 Morgon L. Crow ATTORNEY United States Patent 3,276,793 DUAL STRING PACKER CONSTRUCTION Morgan L. Crow, Dallas, Tex., assignor, by mesne assignments, to Dresser Industries, Inc., a corporation of Delaware Original application July 26, 1961, Ser. No. 126,999, new Patent No. 3,215,206, dated Nov. 2, 1965. Divided and this application July 12, 1965, Ser. No. 482,319 1 Claim. (Cl. 285-437) This is a division of application Serial No. 126,999, filed July 26, 1961, now Patent Number 3,215,206.

This invention is concerned with a well packer, and is particularly concerned with means for detachably connecting cylindrical sections of packers having dual parallel passages therethrough for receiving dual strings of tubing extending into a well bore.

The principal object of the invention described and claimed herein is the provision of a novel bayonet type coupling provided between sections of the packer assembly, including the connection between the upper and lower support members of the packer sleeve, the shear pin housing disposed thereabove, and the slip expander head exposed therebelow. Such a bayonet type connection includes inter-fitting male and female members, which are inter-engaged by relative rotation, and when parallel pipes are extended through openings therein, positively locks same against counter-rotation for disengagement. This construction may be utilized in other well applications, where elements are to be connected together and multiple pipes or strings are to be extended therethrough, eliminating the necessity for threaded connections.

The longitudinal passages for the multiple pipes or strings also provide the vacancies in the male and female bayonet members through which the male and female members may be aligned and then rotated to achieve full engagement.

Other and further objects of the invention will become apparent upon reading the detailed specification hereinafter following and by referring to the drawings annexed hereto.

A suitable embodiment of the invention is shown in the attached drawing wherein: 7

FIGURE I is a side elevational view of the dual packer assembly in unset condition;

FIGURE II is a side elevational view of the dual packer assembly with the packer in set condition;

FIGURE III is a diagrammatic, cross-sectional, elevational view showing the dual packer in set condition in a well, with a drillable packer seated therebelow between two zones of production in a well;

FIGURES IV, IVA and IVB are cross-sectional, elevational views of the dual packer assembly attached to the primary string, with the packer in relaxed position, as it would appear while being lowered into the well, and prior to, or after, the setting of the lower packer (not shown);

FIGURE V is a transverse, cross-sectional view taken on the line V-V of FIG. IV, showing two oppositely disposed hydraulic pistons, with passages communicating with the rear thereof fromthe secondary passage;

FIGURES VI and VIA are cross-sectional, elevational views of the packer assembly taken on the line VIVI of FIGURES IV, IVA and IVB;

FIGURE VII is a transverse, cross-sectional view taken on the line VII-VII of FIG. IV;

FIGURE VIII is a transverse, cross-sectional view taken on the line VIII-VIII of FIGURE IVA;

FIGURE IX is a transverse, cross-sectional view taken on the line IX-IX of FIGURE IXA;

FIGURE X is a transverse, cross-sectional view taken on the line XX of FIGURE IVA;

3,275,793 Patented Oct. 4, 1966 "ice FIGURE XI is a transverse, cross-sectional view taken on the line XIXI of FIGURE IVB;

FIGURES XH, XIIA and XIIB are a cross-sectional, elevational view similar to FIGURES IV, IVA and WE, showing the dual packer assembly as it appears in set condition, with the secondary string attached thereto;

FIGURE XIII is a transverse, cross-sectional view taken on the line XIIIXIII of FIGURE XII;

FIGURES XIV and XIVA are a cross-sectional, elevational view of the packer assembly, similar to FIGURES VI and VIA, showing the packer assembly in set condition;

FIGURE XV is a transverse, cross-sectional view taken on the line XVXV of FIGURE IVB; and

FIGURE XVI is a perspective exploded view of the latch spring housing and the upper packer support, illustrating the bayonet connection between such two members.

Numeral references are employed to designate the various parts shown in the drawings, and like numerals indicate like parts'throughout the various figures of the drawlIlgS.

FIGURE III is a schematic representation of the packer and tubing arrangement employed with the dual string packer of the type herein described, as it would appear when set in the casing.

The numeral 1 indicates a well casing which extends into a well bore from the earths surface.

The dual packer body is generally indicated at 2, which has a packer sleeve 3 of resilient material disposed thereabout, which is compressed and expanded into sealing engagement with the inner wall of the casing 1. The packer assembly is anchored to the casing wall by means of toothed slips 4, the teeth on which are forced against the casing wall in penetrating engagement therewith.

The body 2 has two parallel, longitudinal passages 5 and 6 therethrough.

A tubular member 7, which usually includes a mandrel with a tubing string attached at the upper and lower ends thereof, extends through the passage 5. Such tubular member 7 communicates, through a tubing string, extending therethrough, with the earths surface and is attached at its lower end to a tubing string which in turn is attached in the bore of a lower packer 8.

The packer 8 is of the drillable type which may be run and set either on a tubing string or on a wire line and expanded by pressure fluid released therein or by mechanical force. The packer body 8 is anchored to the casing wall 1 by means of upper toothed slips 9 and lower toothed slips 10, and has extended thereabout a resilient packer sleeve 11, which is expanded into sealing engagement with the wall of casing 1.

Tubing string 7 below the dual packer may be disengageably attached to the packer body 8 in communication with the passage therethrough by means of a stinger 9a which may be latched or threaded thereinto. As previously explained, the tubing string 7 is arranged to rotate in the packer body 2, to permit the stinger 9a to be rotated, when necessary, into and out of threaded engagement with the packer body 8.

A packing nipple or connection 12 is attached in the passage through the packer body 8 and may be attached at its lower end to a screen pipe, standing valve or other contrivance which permits production fluid to pass through the passage through the packer body 8 and upwardly through the tubing string 7.

A stinger 13, attached to the lower end of a secondary string of tubing 20, extending to the earths surface, has an expandable split ring 15 disposed thereabout which is arranged to be contracted, and allowed to expand outwardly into an annular recess 14 in the upper end of the passage 6 to disengageably latch the stinger 13 in communication with the passage 6, and thereby disengageably latch the secondary tubing string 20 to the packer body 2, so that downward force may be exerted through the secondary tubing string 20-upon the packer body 2, to un- V latch the body from the mandrel of the primary string 7 to permit the packer body to be moved downwardly over the primary mandrel and expand and set the packer against the casing wall, in the manner which will be hereinafter described.

A suitable seal 16 is arranged about the lower end of the stinger 13 to provide a seal between the outer wall of the stinger and the inner wall of the passage 6.

The upper end of the body 2, about the passage 6,.

comprises a landing scoop 17, which has an inwardly converging entry surface thereabout to guide the stinger 13 into the landing scoop 17.

The lower packer 8 may be first run into the well and set above a lower zone of production at a suitable elevation. The primary string of tubing is then made up and run into the well, with the dual packer 2 in suitable spaced relationship above the lower packer 8. Before the upper dual packer is set the stinger 9a is guided into and latched in the lower packer 8. The string of tubing 7 may be rotated, if desired, through the upper packer 2 to engage and disengage the stinger 9a with the lower packer.

The upper packer 2 is so spaced from the lower packer 8, that the upper packer is disposed above an upper zone of production which communicates with the tubing casing annulus in the area indicated at 19 through perforations 19a.

To set the upper packer 2, the secondary string 20 is made up and run into the well with the stinger 13 attached to the lower end thereof. The stinger 13 is guided into the landing scoop 17 and locked therein, and downward force is exerted through the secondary string 20 upon the packer body 2,.to thereby force the body downwardly over the mandrel of pipe 7, extending through the primary passage of the body 2 to thereby unlatch the body 2 from the primary mandrel of tubing 7,and allow the body'2 to be moved downwardly over the primary mandrel to expand the slips 4 into engagement with the casing and expand and seal the resilient sleeve 3 against the wall of the casing by increased downward force exerted upon secondary string 20.

It will be seen that when the packers 8 and 2 are set in the well, the tubing string 7 communicates with a lower zone of production below the packer 8 and thetubing string 20 communicates with an upper zone through the passage 6 extending through the packer 2.

The foregoing is a general description of the purpose, operation and function of the packer apparatus herein described for dual completions, and the following is a detailed description of the specific apparatus for constructing and operating the novel dual packer.

FIGURE I shows the dual packer assembly as it would appear while being lowered into the casing on the string of tubing 21, and before it is set in the casing. FIGURE II shows the packer assembly as it would-appear in the casing string, after the stinger 13 has been lowered into the casing on the string of tubing 20, latched into the body of the. packer, and force has been exerted downwardly on the packer body through tubing 20, to unlatch same from the mandrel of tubular member 7'to move the packer body downwardly over the, mandrel, to expand the slips into anchoring engagement with the casing, and expand the resilient seal member, about the packer, into sealing engagement with the casing.

The assembly, as shown in these drawings, includes the landing scoop 17 attached to the anchor body 22 by capv screws 84 (FIG. XIII).

The anchor body 22 and the landing scoop 17 have provided in the wall of the anchor body 22, and are arranged to move outwardly in response to pressure from 7 landing scoop 17 and anchor body 22, and is connected to the anchor body 22 by means of bolts 54 extending through counter-sunk passages 53, and threadedly engaged in holes 55 in the lower face of the anchor body 22, as indicated at 55 (see FIG. XIV).

The packer sleeve, generally indicated at 3, is preferably made up of a plurality of superposed discs or segments 26 made of resilient material, such as rubber or synthetic rubber material, and have parallel passages therethrough arranged to receive the mandrels or tubular members extending through the packer device.

The resilient segments 26 are disposed between disclike support members 27 and 28. The upper support disc 27 is attached to the latch spring housing by a bayonet connection, which will be described in more detail hereinafter, and the lower disc support member 28 is attached to the slip expander head 29by a similar bayonet type connection.

The slip expander head 29 is suspended on a shoulder 77 provided on the secondary mandrel 76 (FIGJIVA) in the manner hereinafter described, and is arranged to be moved downwardly. Head 29 has outwardly diverging surfaces 29a on opposite sides thereof, which ,co-act with the guided slips 31 to move the slips outwardly into anchoring engagement with the casing wall when head 29 moves downwardly.

The slips 31 are slidably connected to a slip support housing 30, which housing 30 is frangibly connected to the mandrel section 42, extending through the packer body, by means of shear screws 30a (FIG. XI). The shear screws 30a have inner ends which are engaged in a recess on a shoulder 32 provided about the mandrel section 42, and such inner ends are weakened so that they may be broken to release the slip supporting housing 30 from the mandrel 42 upon exertion of a predetermined force thereon.

An adjusting sleeve 33 is threadedly engaged in the lower end of the slip supporting housing 30,'and is arranged to engage a shoulder 82 provided about the lower mandrel section 42 to provide. for proper adjusted relationship between the mandrel and the other parts of the packer. After the adjusting sleeve 33 :has been positioned in proper adjusted relationshipagainst the shoulder 82, it may be fixed in place by set screws 33a extending through the wall of the housing 30.

The toothed slips 31 are slidably connected to the tapered surfaces 29a on the expander, head .29 by means,

The mandrel section 42 is attached to the tubing string extending below the dual packer 2 by means of a conventi-onal coupling 39 and the upper end of the mandrel 7 is attached to the tubing string 21,:extending above the vpacker assembly, by means of a conventional coupling 40.

Referring to FIGURES IV-IVB, the primary mandrel or tubular member 7, passing through the packer 2, is divided into two sections, an upper section 41 and a lower section 42, connected by a coupling 43.

An expander ring 44 is secured about the lower end of the mandrel section 41, and is positioned between an annular shoulder provided about the mandrel section 41 and the upper end of the coupling 43. Said expander head 44 has a tapered surface 45 about the upper, outer end thereof, for the purpose of guiding and expanding the latch ring 47 thereover, in the manner hereinafter described.

An annular recess 46 is provided in the upper end of the primary bore 5 extending through the latch housing in which is disposed the split spring latch 47, which extends about the mandrel section 41. It will be noted that the spring latch 47, in relaxed position as shown in FIG. IV, is engaged between the lower end 49 of the anchor body 22 and the upper end of expander ring 44 to thereby disengageably suspend the body to the primary mandrel 41-42.

An annular shoulder 50 is provided in the lower end of the latch spring housing 25 against which the lower end of the coupling 43 is positioned to limit downward movement of the mandrel 7 with reference to the body of the packer assembly, to permit the packer to be retrieved from the hole upon relaxing the packer and pulling upwardly on the secondary string 20.

An annular pickup shoulder 51 is provided inside the anchor body 22 which is engageable with the expander ring 44 to permit the packer device to be picked up and withdrawn from the hole on the primary string 21 upon emergency release procedure hereinafter described.

It will be seen that when force is exerted downwardly upon the packer body by the secondary string 20 in the manner hereinafter described, the packer body 2 is caused to move downwardly and the tapered surface 48 on the inner side of the lower end of the spring latch ring 47 engages the tapered surface on the upper, outer end of the expander ring 44, expanding the latch spring 47 outwardly into the recess 46, to unlatch the packer body from the primary mandrel 7, to thereby allow the packer body 2 to move downwardly with reference to the primary mandrel to expand the packer sleeve 3.

The initial downward movement of the packer housing 2 over the primary mandrel 7, moves the expander head 29 downwardly, causing the outward movement of the slips 31 into anchoring engagement with the casing 1, and further downward movement thereof expands the packer sleeve 3 between the packer support rings 27 and 28 into sealing engagement with the casing.

An auxiliary anchoring means is provided by the hydraulically actuated piston slips 23 which are mounted in appropriate sockets 56 provided in the outer wall of the anchor housing 22.

The piston slips 23 have teeth 57 on the outer surfaces thereof, and are provided with seal rings 58 extending thereabout which slidably seal against the inner walls of the sockets 56.

Inter-communication is provided between the sockets 56 at the rear of the pistons 23 by means of passages 59, which passages are in communication with pressure ports 60 (FIG. V) extending through the anchor body wall and communicating with the longitudinal bore 6 through the packer body.

It will be seen that pressure from below the packer in the annular space 19 will be transmitted through the bore 6 and through the ports 60 and passages 59 to the rear of the piston slips 23, to cause them to move outwardly into anchoring engagement with the casing wall.

The straps 24 extend through vertical slots in the face of the piston teeth, said straps being attached to the outer wall of the anchor housing 22 by means. of suitable screws 61.

Springs 24a are disposed in recesses provided in the outer faces of pistons 23 and the outer ends thereof are positioned against the straps 24, to normally urge the piston teeth inwardly of the sockets 56, so as to norm-ally maintain the pistons in said recesses when no pressure is exerted against the rear sides thereof.

It will be seen that the greater the pressure exerted from below the packer through the bore 6, the greater the anchoring force will be exerted against the piston slips 23 to prevent the packer from being moved upwardly and unseated by pressure from below. The slips 31 anchor the packer device against movement in response to downward pressure. The packer device is thus positively anchored against both upward and downward pressure.

A novel bayonet joint connection is provided between the packer support rings 27 and 28 and the respective members to which they are attached.

As shown in FIG. XVI, the support ring 27 has dual passages 67 and 68 therethrough arranged to receive the secondary mandrel 76 and the primary mandrel section 42, respectively.

Disposed on the upper face of the support ring 27 is a male bayonet pin member 62, having opposed radiused ends thereon, with slots 63 provided thereabout. The radiused ends of member 62 are arranged to be inserted in the cylindrical passages 65 and 66 in the lower end of the latch housing 25 until the ribs 62a provided by the slots 63 come into alignment with corresponding slots 64 in the inner end of the latch housing 25, whereupon the support ring 27 may be rotated to cause the ribs 62a to enter the slots 64 and to bring the passages 67 and 68 into alignment with the passages 65 and 66 through the latch housing 25. The mandrels 76 and 42 may then be extended through the aligned passages 67, 68, 65 and 66, to prevent relative rotation and thereby lock the elements 25 and 27 together against disengagement until the mandrels are removed from such passages. This provides a quick and simple means of assembly of parts in multiple packer devices and in similar equipment without the use of bolts or screw or threads, and provides a positive means for engagement, and ease in disengagement when it is necessary to disassemble these parts.

The lower support ring 28 is attached to the expander head 29 by the same type of bayonet joint connection as hereinbefore described, wherein the female groove is indicated at 69 and the male rib is indicated at 70, providing such bayonet type connection.

The secondary passage through the packer body 2 includes a tubular mandrel 76 extending therethrough which is threadedly engaged at its upper end to the anchor housing 22, and includes an annular pickup shoulder 77 thereon, which is engageable with an annular shoulder 78 inside the expander head 29, to suspend the expander head thereto and to provide a means for picking up the expander head when the packer is retrieved from the casing.

The stinger 13 includes a coupling head 71 having an annular shoulder 74 thereon engageable with a corresponding shoulder 74a, provided about the upper end-of the secondary passage in the landing scoop 17.

The coupling head 71 is threadedly engaged to a spacer tube 72, which in turn is connected to the secondary tubing string above the packer by means of a conventional coupling 73.

A seal tube 75, having seal rings 16 disposed thereabout, is threadedly engaged to head 71 and may be inserted into the secondary bore of the landing scoop 17 in order to seal between the stinger device and such bore. An 0 ring seal 85 is provided between the lower end of head 71 and the secondary bore of scoop 17 to prevent foreign material from collecting about the latch ring 15 and rendering it inoperable.

The stinger device 13 is lowered into the well on the secondary string 20 and is landed and latched in the secondary bore of the landing scoop 17, by guiding the seal tube thereinto. When the split latch ring 15 contacts the tapered entry surface in the upper end of the landing scoop, such ring will be elastically retracted inwardly to move into the secondary bore of such landing scoop, and when such ring reaches the annular recess 14, it will expand thereinto, and at the same time the shoulders 74 and 74a come into contact to permit the down- 

